Human Impacts—Nonpoint Source Pollution

Summary: Nonpoint source pollution (NSP) comes from many diffuse sources, and is a leading cause of water quality problems in the U.S.. In this topic guide, students identify different types of NSP and their effects on water quality.

Concepts to teach: Nonpoint source pollution, runoff, point source pollution, toxins, biomagnification, eutrophication

Goals: Students learn about many sources and impacts of nonpoint source pollution and their impact on local and distant waters. They identify how personal behavior and community practices can contribute to nonpoint source pollution.

S.06.3S.1, S.06.3S.2
S.07.3S.1, S.07.3S.2, 7.3S.3
S.08.3S.1, S.08.3S.2


Specific Objectives:

  1. Identify the difference between point and nonpoint source pollution, and give examples of each.
  2. Conduct an inquiry to determine the effects of a type of nonpoint source pollution on water quality.
  3. Describe how local nonpoint source pollution affects ocean health.

Activity Links and Resources:

  • Nonpoint Source Pollution tutorial—This extensive resource from the NOAA ocean service education pages provides definitions, history, methods used to detect nonpoint source pollutants, and ways to assess and reduce their damaging effects on the environment.
  • StreamWebs—This OSU Extension student stewardship network provides open-source, web-based tools for watershed data management, analysis and networking for teachers and students. Use the provided data sheets and protocols to determine the extent to which nonpoint source pollution and other human impacts may affect local stream health. Compare data within a stream, and to other student studies posted on the StreamWebs website.
    • Water Quality Data: Measure and compare temperature, dissolved oxygen, pH, and turbidity in nearby stream(s).
    • Macroinvertebrate Data: Assess stream health based on the types and numbers of macroinvertebrates found.
  • Classroom inquiry—The EPA Brochure “Ideas for Science Fair Projects on Surface Water Quality Topics” lists several simple inquiry projects for a classroom or student groups to undertake. Topics include:
    • Fertilizers and algal growth
    • Effect of stream health on macroinvertebrate diversity
    • The effect of “first flush” on water quality
    • The effect of buffers on water quality
    • Cleaners and their effect on water quality
  • US Environmental Protection Agency’s Articles and Activities for Middle School Students—A collection of classroom materials relating to an issue of nonpoint source pollution in the U.S.. Most use case studies used are from regions outside the Pacific Northwest.
    • After the Storm—30 minute video co-produced by EPA and The Weather Channel, with supporting resources
  • Excess nutrients
  • NOAA Ocean Explorer curriculum


  • Publish water quality data on the StreamWebs website and compare findings to results found by other classrooms.
  • Reflective assessment ideas included in the Traveling Nitrogen activity.
  • Describe how local water quality issues affect ocean health.